Planned experiments with genetically modified fruit flies in Brazil could lead to genetically modified maggots in fruit being illegally imported to European countries, including Britain, the Netherlands, Spain, Germany, France and Italy, writes Helen Wallace.

When released, the GM fruit flies are expected to mate with wild flies and produce female offspring which fail to reach adulthood, with many dying as maggots in the fruit. This is intended to reduce the wild population of Mediterranean fruit flies, which are a pest which feeds on many types of fruit. To reduce the wild population it must be outnumbered by a factor of at least ten to one, requiring many millions of GM fruit flies to be released.

Brazil exports fruit including melons, mangoes, grapes, apples, papayas and plums worldwide, with Europe as a major market. In 2013, the British and Dutch made almost two thirds of purchases, followed by Spain, the U.S., Germany, Portugal, France, Uruguay, the UAE, Canada, Bangladesh, Italy and Argentina.

In the European Union, food containing genetically modified organisms (GMOs) is legally required to be safety tested and labelled, however no specific procedures have been adopted to identify GM maggots in fruit imports. Live GM flies could also be transported in the fruit as the genetic killing mechanism affects only female flies. Transport in fruit and other produce is a major route for pests to spread worldwide.

The date for the planned experiments has not yet been announced. But European consumers and food safety authorities should be alert to a serious problem with fruit imports if the experiments in Brazil go ahead as planned.